Cooling Issues - Loss of water

[Jimmy1]

Hey mate, you only have 2-3 litres because there's about another 5-6 in the block and heads and another litre in the heater core ,to properly flush the cooling system (this is based on my EF falcon, which is very touchy to not flushing and bleeding the cooling system)you need to remove the thermostat and disconnect the bottom radiator hose, and get your garden hose and wrap some rags around it, then shove it in the top radiator outlet and turn on the tap and let the water flow until the water is clear, also when you are bleeding the system does the water come out steady or does it splutter and throw only small amount of water out, if so that's air pockets being expelled from the cooling system, also try to keep the front of the car up on a angle, it will help move air pockets towards the front of the motor which would make the process much easier, hope this helps
P.

Cheers for the reply mate. I'm not too keen on removing the thermostat again as its located on the back of the motor and it took a solid 6+ hours to get it off a few weeks back when we had to replace it.

 

[Jimmy1]

And this **** is ongoing... The system is holding water, but when the system is fully cooled it is still under pressure... So whenever i go to take the cap off to check the levels at the engine fill up point, it dumps a bunch of water into the overflow reservoir. This Coolant then doesn't re-siphon back into the cooling system... any suggests?

 

[Muke]

I found if you try just filling the thing by pouring coolant into the cap, you'll get air pockets and wont get anywhere near enough coolant in. I took the hose off and poured into the hose until the coolant was pushed all the way through the radiator and block and started flowing out the inlet. Jam the hose on and top up the little bit left through the cap. Then fill the reservoir, run the engine up to temp. Then check the level in the reservoir before you drive it next time just in case. If you've got air in there and then try that, you can push some coolant out before you get all the air out. What you can do if it appears near full, is take the cap off and squeeze the bottom hose a few times. Not crush it, just to bounce the coolant level a few times. If the level drops, you've got air in it. That's about the limit of my experience. The tip about getting a pressure test done is a good one if you can't find anything.

edit: That's on an alloytec motor.

 

[Joelene]

Bottom radiator hose should get most of the coolant out of engine and radiator.

Sounds to me like you have not filled the system completely due to air being trapped.

I would go through the motions of filling the radiator from a height. A reverse 2 litre coke bottle with bottom cut off for a coolant filler for a start.

Then bleed the system at the thermostat with engine running and also the plastic screw at the front top corner of the radiator.

Once the air is gone you will get the remaining coolant in.

The reason the radiator level drops is because the thermostat opens and lets water into the engine from the radiator when warm so you are thinking you are losing coolant when in fact it's doing its job. But you need to get the remaining coolant IN so if it's working, keep filling the radiator and driving it until it doesn't drop any more.

 

[Joelene]

Remove Bottom radiator hose should get most of the coolant out of engine and radiator. But don't bother if you are trying to expel air as this lets air IN......

Sounds to me like you have not filled the system completely due to air being trapped.

I would go through the motions of filling the radiator from a height. A long tube and funnel about head height

When radiator is full, bleed the system at the thermostat with engine running and also the plastic screw at the front top corner of the radiator. You could also take off the top water pump hose and fill the engine cold that way....

Once the air is gone you will get the remaining coolant in.

The reason the radiator level drops is because the thermostat opens and lets water into the engine from the radiator when warm so you are thinking you are losing coolant when in fact it's doing its job. But you need to get the remaining coolant IN so if it's working, keep filling the radiator and driving it until it doesn't drop any more.

The fans turn on at different temperatures. Probably the first comes on at 100C and the next at 105C or similar. One comes on with the aircon anyway.

If you have the steering wheel audio controls, hold the left scroll button down then turn ignition on then release. This will bring the diagnostics up on the LCD in the dash. Use the left scroll to scroll through to engine temp and watch the temps rise in degrees. Then you can see at what point each fan switches on according to temperature.

When you see the temp drop this is the thermostat opening. The temp should fall back to around 90-100C.